configure

#!/usr/bin/env bash

set -o errexit
set -o pipefail

# shellcheck disable=SC2155
export PROJECT_DIR=$(git rev-parse --show-toplevel)

# shellcheck disable=SC2155
export SOPS_AGE_KEY_FILE=~/.config/sops/age/keys.txt

# shellcheck disable=SC1091
source "${PROJECT_DIR}/.config.env"

show_help() {
cat << EOF
Usage: $(basename "$0") <options>
    -h, --help                      Display help
    --verify                        Verify .config.env settings
EOF
}

main() {
    local verify=

    parse_command_line "$@"

    verify_binaries

    if [[ "${verify}" == 1 ]]; then
        verify_metallb
        verify_addressing
        verify_age
        verify_git_repository
        verify_cloudflare
        verify_success
    else
        # generate sops configuration file
        envsubst < "${PROJECT_DIR}/tmpl/.sops.yaml" \
            > "${PROJECT_DIR}/.sops.yaml"

        # generate cluster settings
        envsubst < "${PROJECT_DIR}/tmpl/kubernetes/flux/cluster-settings.yaml" \
            > "${PROJECT_DIR}/kubernetes/flux/vars/cluster-settings.yaml"

        envsubst < "${PROJECT_DIR}/tmpl/kubernetes/flux/cluster.yaml" \
            > "${PROJECT_DIR}/kubernetes/flux/config/cluster.yaml"

        # generate secrets
        envsubst < "${PROJECT_DIR}/tmpl/kubernetes/cluster-secrets.sops.yaml" \
            > "${PROJECT_DIR}/kubernetes/flux/vars/cluster-secrets.sops.yaml"
        sops --encrypt --in-place "${PROJECT_DIR}/kubernetes/flux/vars/cluster-secrets.sops.yaml"

        envsubst < "${PROJECT_DIR}/tmpl/kubernetes/cert-manager-secret.sops.yaml" \
            > "${PROJECT_DIR}/kubernetes/core/cert-manager/cert-manager/issuers/secret.sops.yaml"
        sops --encrypt --in-place "${PROJECT_DIR}/kubernetes/core/cert-manager/cert-manager/issuers/secret.sops.yaml"

        envsubst < "${PROJECT_DIR}/tmpl/kubernetes/external-dns-secret.sops.yaml" \
            > "${PROJECT_DIR}/kubernetes/core/networking/external-dns/app/secret.sops.yaml"
        sops --encrypt --in-place "${PROJECT_DIR}/kubernetes/core/networking/external-dns/app/secret.sops.yaml"

        envsubst < "${PROJECT_DIR}/tmpl/terraform/secret.sops.yaml" \
            > "${PROJECT_DIR}/terraform/cloudflare/secret.sops.yaml"
        sops --encrypt --in-place "${PROJECT_DIR}/terraform/cloudflare/secret.sops.yaml"

        setup_github_webhook
        setup_weave_gitops
        success
    fi
}

parse_command_line() {
    while :; do
        case "${1:-}" in
            -h|--help)
                show_help
                exit
                ;;
            --verify)
                verify=1
                ;;
            *)
                break
                ;;
        esac

        shift
    done

    if [[ -z "$verify" ]]; then
        verify=0
    fi
}

_has_binary() {
    command -v "${1}" >/dev/null 2>&1 || {
        _log "ERROR" "${1} is not installed or not found in \$PATH"
        exit 1
    }
}

_has_optional_envar() {
    local option="${1}"
    # shellcheck disable=SC2015
    [[ "${!option}" == "" ]] && {
        _log "WARN" "Unset optional variable ${option}"
    } || {
        _log "INFO" "Found variable '${option}' with value '${!option}'"
    }
}

_has_envar() {
    local option="${1}"
    # shellcheck disable=SC2015
    [[ "${!option}" == "" ]] && {
        _log "ERROR" "Unset variable ${option}"
        exit 1
    } || {
        _log "INFO" "Found variable '${option}' with value '${!option}'"
    }
}

_has_valid_ip() {
    local ip="${1}"
    local variable_name="${2}"

    if ! ipcalc "${ip}" | awk 'BEGIN{FS=":"; is_invalid=0} /^INVALID/ {is_invalid=1; print $1} END{exit is_invalid}' >/dev/null 2>&1; then
        _log "INFO" "Variable '${variable_name}' has an invalid IP address '${ip}'"
        exit 1
    else
        _log "INFO" "Variable '${variable_name}' has a valid IP address '${ip}'"
    fi
}

verify_addressing() {
    local found_ingress="false"

    # Verify the metallb min and metallb ceiling are in the same network
    metallb_subnet_min=$(echo "${BOOTSTRAP_METALLB_LB_RANGE}" | cut -d- -f1 | cut -d. -f1,2,3)
    metallb_subnet_ceil=$(echo "${BOOTSTRAP_METALLB_LB_RANGE}" | cut -d- -f2 | cut -d. -f1,2,3)
    if [[ "${metallb_subnet_min}" != "${metallb_subnet_ceil}" ]]; then
        _log "ERROR" "The provided MetalLB IP range '${BOOTSTRAP_METALLB_LB_RANGE}' is not in the same subnet"
        exit 1
    fi

    # Depending on the IP address, verify if it should be in the metallb range or not
    metallb_octet_min=$(echo "${BOOTSTRAP_METALLB_LB_RANGE}" | cut -d- -f1 | cut -d. -f4)
    metallb_octet_ceil=$(echo "${BOOTSTRAP_METALLB_LB_RANGE}" | cut -d- -f2 | cut -d. -f4)
    for (( octet=metallb_octet_min; octet<=metallb_octet_ceil; octet++ )); do
        addr="${metallb_subnet_min}.${octet}"
        if [[ "${addr}" == "${BOOTSTRAP_METALLB_INGRESS_ADDR}" ]]; then
            found_ingress="true"
        fi
    done

    if [[ "${found_ingress}" == "false" ]]; then
        _log "ERROR" "The IP for ingress '${BOOTSTRAP_METALLB_INGRESS_ADDR}' should be in the provided metallb range '${BOOTSTRAP_METALLB_LB_RANGE}'"
        exit 1
    fi
}

verify_age() {
    _has_envar "BOOTSTRAP_AGE_PUBLIC_KEY"
    _has_envar "SOPS_AGE_KEY_FILE"

    if [[ ! "$BOOTSTRAP_AGE_PUBLIC_KEY" =~ ^age.* ]]; then
        _log "ERROR" "BOOTSTRAP_AGE_PUBLIC_KEY does not start with age"
        exit 1
    else
        _log "INFO" "Age public key is in the correct format"
    fi

    if [[ ! -f ~/.config/sops/age/keys.txt ]]; then
        _log "ERROR" "Unable to find Age file keys.txt in ~/.config/sops/age"
        exit 1
    else
        _log "INFO" "Found Age public key '${BOOTSTRAP_AGE_PUBLIC_KEY}'"
    fi
}

verify_binaries() {
    _has_binary "envsubst"
    _has_binary "flux"
    _has_binary "git"
    _has_binary "age"
    _has_binary "helm"
    _has_binary "ipcalc"
    _has_binary "jq"
    _has_binary "gitops"
    _has_binary "yq"
    _has_binary "sops"
    _has_binary "ssh"
    _has_binary "task"
    _has_binary "terraform"
    _has_binary "tflint"

    if ! [[ "$(sops --version)" =~ 3\.[0-9]+\.[0-9]+ ]]; then
        _log "ERROR" "Incompatible sops version, make sure you are using the latest release of github.com/mozilla/sops"
        exit 1
    fi

    if ! [[ "$(yq --version)" =~ 4\.[0-9]+\.[0-9]+ ]]; then
        _log "ERROR" "Incompatible yq version, make sure you are using the latest release of github.com/mikefarah/yq"
        exit 1
    fi
}

verify_metallb() {
    local ip_floor=
    local ip_ceil=
    _has_envar "BOOTSTRAP_METALLB_LB_RANGE"
    _has_envar "BOOTSTRAP_METALLB_INGRESS_ADDR"

    ip_floor=$(echo "${BOOTSTRAP_METALLB_LB_RANGE}" | cut -d- -f1)
    ip_ceil=$(echo "${BOOTSTRAP_METALLB_LB_RANGE}" | cut -d- -f2)

    _has_valid_ip "${ip_floor}" "BOOTSTRAP_METALLB_LB_RANGE"
    _has_valid_ip "${ip_ceil}" "BOOTSTRAP_METALLB_LB_RANGE"
    _has_valid_ip "${BOOTSTRAP_METALLB_INGRESS_ADDR}" "BOOTSTRAP_METALLB_INGRESS_ADDR"
}

verify_git_repository() {
    _has_envar "BOOTSTRAP_GIT_REPOSITORY"

    export GIT_TERMINAL_PROMPT=0
    pushd "$(mktemp -d)" >/dev/null 2>&1
    [ "$(git ls-remote "${BOOTSTRAP_GIT_REPOSITORY}" 2> /dev/null)" ] || {
        _log "ERROR" "Unable to find the remote Git repository '${BOOTSTRAP_GIT_REPOSITORY}'"
        exit 1
    }
    popd >/dev/null 2>&1
    export GIT_TERMINAL_PROMPT=1
}

setup_github_webhook() {
    _has_envar "BOOTSTRAP_FLUX_GITHUB_WEBHOOK_SECRET"

    WEBHOOK_SECRET="${BOOTSTRAP_FLUX_GITHUB_WEBHOOK_SECRET}"

    if [[ "${WEBHOOK_SECRET}" == "generated" ]]; then
        WEBHOOK_SECRET="$(openssl rand -base64 30)"
    fi

    export BOOTSTRAP_FLUX_GITHUB_WEBHOOK_SECRET="${WEBHOOK_SECRET}"
    _log "INFO" "Using GitHub Token '${WEBHOOK_SECRET}' for Flux"

    envsubst < "${PROJECT_DIR}/tmpl/kubernetes/github-webhook-token-secret.sops.yaml" \
        > "${PROJECT_DIR}/kubernetes/core/flux-system/addons/webhooks/github/secret.sops.yaml"
    sops --encrypt --in-place "${PROJECT_DIR}/kubernetes/core/flux-system/addons/webhooks/github/secret.sops.yaml"
}

setup_weave_gitops() {
    _has_envar "BOOTSTRAP_WEAVE_GITOPS_ADMIN_PASSWORD"

    WEAVE_GITOPS_ADMIN_PASSWORD="${BOOTSTRAP_WEAVE_GITOPS_ADMIN_PASSWORD}"

    if [[ "${WEAVE_GITOPS_ADMIN_PASSWORD}" == "generated" ]]; then
        WEAVE_GITOPS_ADMIN_PASSWORD="$(openssl rand -base64 30)"
    fi

    export BOOTSTRAP_WEAVE_GITOPS_ADMIN_PASSWORD="${WEAVE_GITOPS_ADMIN_PASSWORD}"
    _log "INFO" "Using admin password '${WEAVE_GITOPS_ADMIN_PASSWORD}' for Weave Gitops"

    # Convert password to bcrypt hash
    export BOOTSTRAP_WEAVE_GITOPS_ADMIN_PASSWORD="$(echo -n "${BOOTSTRAP_WEAVE_GITOPS_ADMIN_PASSWORD}" | gitops get bcrypt-hash)"

    envsubst < "${PROJECT_DIR}/tmpl/kubernetes/weave-gitops-secret.sops.yaml" \
        > "${PROJECT_DIR}/kubernetes/core/flux-system/weave-gitops/app/secret.sops.yaml"
    sops --encrypt --in-place "${PROJECT_DIR}/kubernetes/core/flux-system/weave-gitops/app/secret.sops.yaml"
}

verify_cloudflare() {
    local account_zone=
    local errors=

    _has_envar "BOOTSTRAP_CLOUDFLARE_APIKEY"
    _has_envar "BOOTSTRAP_CLOUDFLARE_DOMAIN"
    _has_envar "BOOTSTRAP_CLOUDFLARE_EMAIL"

    # Try to retrieve zone information from Cloudflare's API
    account_zone=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=${BOOTSTRAP_CLOUDFLARE_DOMAIN}&status=active" \
        -H "X-Auth-Email: ${BOOTSTRAP_CLOUDFLARE_EMAIL}" \
        -H "X-Auth-Key: ${BOOTSTRAP_CLOUDFLARE_APIKEY}" \
        -H "Content-Type: application/json"
    )

    if [[ "$(echo "${account_zone}" | jq ".success")" == "true" ]]; then
        _log "INFO" "Verified Cloudflare Account and Zone information"
    else
        errors=$(echo "${account_zone}" | jq -c ".errors")
        _log "ERROR" "Unable to get Cloudflare Account and Zone information ${errors}"
        exit 1
    fi
}

verify_success() {
    _log "INFO" "All checks passed!"
    _log "INFO" "Run the script without --verify to template all the files out"
    exit 0
}

success() {
    _log "INFO" "All files have been templated, proceed to the next steps outlined in the README"
    exit 0
}

_log() {
    local type="${1}"
    local msg="${2}"
    printf "[%s] [%s] %s\n" "$(date -u)" "${type}" "${msg}"
}

main "$@"